Method of making pickets from palm fronds



Jan. 25, 1955 v M. l- BIRNIE METHOD OF MAKING PICKETS FROM PALM FRONDS Filed April' 21, 1953 E 3 ME k V 0 7 m r m 4 R, 0 MW. MW m MIHIMIH N IH min-NIH United States Patent METHOD OF MAKING PICKETS FROM PALM FRONDS My invention relates to the making of fence pickets and similar articles from the fronds of palm trees.

In the tropic regions, and in various sections of the southern and western parts of the United States, palm trees grow prolifically, and are grown extensively for their ornamental as well as their commercial values. In many varieties, the fronds have a heavy central petiole or main rib from which the blade or leaf portions extend. The petiole itself is of a tough fibrous character; and when cured, has strength capable of carrying substantial stress. The lower fronds are usually trimmed from palms from time to time as they wilt and droop. Heretofore, the fronds so trimmed have had little or no utility; and, in many communities, the disposal of the fronds after cutting presents a material problem. I have found that by appropriate treatment, the fronds can be converted to a useful commercial product.

It is among the objects of my invention to provide a method of treating palm fronds to make them useful for construction purposes.

Other objects include the utilizing of an otherwise waste material and the converting of it to a useful product of strong, attractive, and inexpensive character suitable for use as fence pickets and similar purposes.

The invention has other objects and features of advantage, some of which with the foregoing will be explained in the following description. It is to be understood that the method of my invention is not limited to the character of apparatus illustrated, as it may be carried out by means other than the form and arrangement of apparatus selected for illustration.

In the drawings:

Figure l is a schematic view of an illustrative arrangement of apparatus by which the method of my invention may be carried out.

Figure 2 is a view of a frond before being treated in accordance with my invention;

Figure 3 is a side view illustrating a trimmed petiole before treatment; and

Figure 4 is a side view illustrating the petiole after treatment.

In accordance with my invention, fronds from palm trees are first subjected to a trimming operation by which the blade or leaf portions of the frond are trimmed from the sides of the petiole of the frond. This may be done manually, or by power trimmers, at a table or other work station.

After trimming, the petioles are subjected to softening and straightening treatments. These treatments are carried out by appropriate apparatus which, in the simple form illustrated schematically in Figure 1 of the drawings, comprises an endless conveyor 4 operating over suitable rollers or pulleys 6 through a chamber 7 and straightening means 8 to a final trimming and packing station.

The petiole portion of each frond normally has a relatively broad fan shaped base 9 which tapers into a long body 10 which curves more or less regularly from the base to the outer tip. The curvature is substantially confined to a plane passing through the axis of the frond normal to the width of the frond; and there is little or no curvature laterally from that plane. In trimming the fronds, the outer end of each frond is trimmed back to about the point where the diameter of the petiole is reduced to the limit of useful size.

The trimmed petioles are placed upon the conveyor with the fan shaped base portions 9 resting flat upon the conveyor 4, the body being disposed substantially parallel to the sides of the conveyor with the curvature arching upwardly from the plane of the conveyor. The petioles are carried in this position through the chamber 7 where they are subjected to the action of heat and moisture. This may be accomplished by passing them through an atmosphere of wet steam; or they may be sprayed with brackish water, or passed through a bath of water, with or without salt or other added chemical agent.

Upon leaving the chamber 7, after a period of treatment suflicient to effect a desired softening of the fibrous structure, the petioles are passed through the straightening means 8 which may comprise a series of rollers; or, as illustrated in Figure 1, may comprise endless pressure belt 12 having its lower reach pressed against the petioles as they are moved thereunder by the conveyor 4. As each petiole is moved to the belt 12, its broad fan shaped base 9 holds the curved portion in upwardly arched position. As the base is drawn under the pressure roller, the body is held against rotative movement, and is flattened to a smooth straight condition.

The conveyor 4 and pressure belt 12 are advanced at the same rate, so that the petioles are held in flattened condition until they pass the end of the pressure belt. The length and rate of movement of the belt 12 is designed to cause the fibers to become substantially set in the straightened condition. The period may be shortened by providing a suitable heating means 14 adjacent the conveyor 4 and/or belt 12. Such heating means may be incorporated in the supporting or guiding structures by which the adjacent reaches of the conveyor and belt are held against vertical displacement beyond the spacing required for flattening the petioles.

After leaving the straightening means, the petioles are received at the table or station, where they may be trimmed to standard lengths, and bundled or otherwise packed for storage or shipment. If desired, the petioles may be placed in presses, or tied and stacked to hold the pieces in straightened condition and to prevent warping until they have become permanently set.

The finished product is particularly suited for use as fence pickets, in which connection, they may be nailed or otherwise secured in various designs of ornamental appearance.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. The method of making fence pickets from palm fronds which comprises trimming blade portions from the sides of the petioles, passing the petioles through a medium by which the fibers of the petioles are softened, and pressing the softened petioles to a flat straight condition.

2. The method of making fence pickets from palm fronds which comprises trimming blade portions from the sides of the petioles, subjecting the petioles to the action of heat and moisture for softening the fibers thereof, and pressing the softened petioles to a flat straight condition.

3. The method of making fence pickets from palm fronds which comprises trimming blade portions from the sides of the petioles, passing the petioles through a softening medium including heated brackish water for softening the fibers thereof, and pressing the softened petioles to a flat straight condition.

4. The method of making fence pickets from palm fronds which comprises trimming blade portions from the sides of the petioles, passing the petioles through a medium by which the fibers of the petioles are softened, and pressing the softened petioles to a flat straight condition, and cutting the straightened petioles to selected lengths.

References Cited in the file of this patent UNITED STATES PATENTS 657,876 Kepner Sept. 11, 1900 812,350 Maxey Feb. 13, 1906 1,958,290 Whiting May 8, 1934 FOREIGN PATENTS 213,095 Switzerland Apr. 1, 1941 

